President Obama has pledged to end America¿s dependence on foreign oil and his administration is spending billions on greener energy initiatives. Few issues are considered more urgent by the White House and average Americans than securing affordable and more environmentally friendly energy sources.

A senior House Democrat from Tennessee issued the first congressional report on geoengineering Friday, just as delegates from 193 nations approved a ban on such research under a global biodiversity treaty.

The debate over whether humans should explore ways to manipulate the climate has taken on increased urgency over the past year, as efforts to curb greenhouse gas emissions linked to global warming have encountered political roadblocks in the United States and elsewhere.

The measure adopted under the Convention on Biological Diversity, which recently concluded in Nagoya, Japan, states "that no climate-related geo-engineering activities that may affect biodiversity take place, until there is an adequate scientific basis on which to justify such activities and appropriate consideration of the associated risks for the environment and biodiversity and associated social, economic and cultural impacts, with the exception of small-scale scientific research studies" under controlled circumstances.

While some scientists and environmentalists have called for geoengineering research as a precautionary measure against catastrophic global warming, activists hailed the moratorium as a way to keep individual actors from altering the climate. The prohibition does not apply to the United States, which has yet to ratify the convention.

House Science and Technology Committee Chairman Bart Gordon (D) said his report was "in no way meant as an endorsement of climate engineering," but instead an effort to give "insight into where existing federal research capacities lie that could be leveraged for these activities."

"Climate engineering carries with it a tremendous range of uncertainties and possibilities, ethical and political concerns, and the potential for catastrophic side effects," Gordon said, adding, "If we find ourselves passing an environmental tipping point, we will need to have done research to understand our options."

The National Science Foundation is best positioned to take the lead on the matter, according to the 56-page report, which also identifies several other agencies that can play a key role.

The National Oceanic and Atmospheric Administration should lead research into ocean fertilization and injecting sulfates into the stratospheric ozone layer, the report states, while the Energy Department should direct high-end computing geoengineering research and "any federal research program into air capture and non-traditional carbon sequestration."

In Japan, delegates to the convention warned that such study should be limited and not stray into actual scientific trials.

"Any private or public experimentation or adventurism intended to manipulate the planetary thermostat will be in violation of this carefully crafted U.N. consensus," said Silvia Ribeiro, Latin American director of ETC Group, a grass-roots advocacy organization.

But Ken Caldeira, an environmental science professor at the Carnegie Institution's Department of Global Ecology who testified before Gordon's panel last year, said countries need to "undertake studies on what we might do" in a climate crisis, given the current trajectory of carbon concentrations in the atmosphere.

"Nobody likes the idea of engineering Earth's climate," Caldeira wrote in an e-mail. "Unfortunately, at some point, our other options may be even more unpleasant."